Investigation of stability of reformulated simethicone emulsion mixed with different doses of NaHCO 3 solution under acidic condition in vitro
It was found that when the pH of reaction endpoint was higher than 5.5, there would be no white precipitation in the vitro experiment (Appendix 1; Appendix 2). In 10 ml of artificial gastric acid, at least 3 ml of 5% NaHCO3 solution mixed with 3 ml of reformulated simethicone emulsion was needed to prevent the development of precipitation (Appendix 1). In 20 ml of artificial gastric acid, at least 5 ml of 5% NaHCO3 solution mixed with 3 ml of reformulated simethicone emulsion was needed to prevent the development of precipitation (Appendix 2). Based on the theory that the average volume of fasting gastric acid was 50 ml and the theoretical maximum volume of gastric acid was 100 ml, the mixed solution containing 30 ml 5% NaHCO3 and 15 ml reformulated simethicone emulsion was chosen to conduct clinical research.
Demographic Characteristics Of Patients
A total of 535 patients were identified and enrolled into the study, out of which twelve patients were excluded; therefore, 523 patients were included in the final analysis (Fig. 3). There was no statistical difference between the demographic characteristics of the two investigated groups. There was also no difference in referral category or clinical indication between the two groups (Table 1).
Table 1
Demographic characteristics of enrolled patients
| Group A(n = 354) | Group B(n = 169) | P-value |
Age, mean ± SD (years) | 48.5 ± 13.2 | 47.5 ± 12.7 | 0.487 |
Sex, n | | | 1.000 |
Male | 201 | 96 | |
Female | 153 | 73 | |
Indication | | | 0.338 |
No obvious symptom | 68 | 37 | |
Screening | 64 | 33 | |
H.plori infection | 3 | 4 | |
Increased serum tumor marker | 1 | 0 | |
Acid regurgitation | 22 | 6 | |
Dyspepsia | 182 | 79 | |
Abdominal pain or discomfort | 62 | 40 | |
Vomit | 1 | 0 | |
Constipation | 0 | 1 | |
Dysphagia | 1 | 0 | |
Gastrointestinal bleeding | 10 | 4 | |
Distention | 8 | 2 | |
Premedication with mixed solution of reformulated simethicone emulsion and 5% NaHCO3 solution can enhance mucosal visibility
White precipitation was not observed during EGD in any patients in Group A. Visibility scores of Group A and Group B for the esophagus (1.12 ± 0.40 vs 1.53 ± 0.59, P < 0.01), gastric fundus (1.23 ± 0.48 vs 1.98 ± 0.73, P < 0.01), gastric angle (1.04 ± 0.22 vs 1.36 ± 0.56, P < 0.01), gastric body (1.39 ± 0.63 vs 2.05 ± 0.76, P < 0.01), gastric antrum (1.10 ± 0.34 vs 1.63 ± 0.70, P < 0.01), duodenum (1.08 ± 0.30 vs 1.47 ± 0.58, P < 0.01) and total visibility score (6.97 ± 1.39 vs 10.01 ± 2.47, P < 0.01) are shown in Table 2. The scores for Group A were significantly lower than that of Group B in terms of visibility for each location as well as the overall visibility, indicating better mucosal visualization for Group A.
Table 2
| Group A(n = 354) | Group B(n = 169) | P-value |
Esophagus | 1.12 ± 0.40 | 1.53 ± 0.59 | < 0.01 |
Gastric fundus | 1.23 ± 0.48 | 1.98 ± 0.73 | < 0.01 |
Gastric angle | 1.04 ± 0.22 | 1.36 ± 0.56 | < 0.01 |
Gastric body | 1.39 ± 0.63 | 2.05 ± 0.76 | < 0.01 |
Gastric antrum | 1.10 ± 0.34 | 1.63 ± 0.70 | < 0.01 |
Duodenum | 1.08 ± 0.30 | 1.47 ± 0.58 | < 0.01 |
Total score | 6.97 ± 1.39 | 10.01 ± 2.47 | < 0.01 |
The influence of premedication with reformulated simethicone emulsion and 5% NaHCO3 solution on the flush times and volume of flush water during EGD
There were significant differences between the flush times for clearing stubborn mucus or bile in the two groups (Table 3). Significantly less time was required in Group A compared to Group B (P < 0.01), in terms of gastric fundus, gastric angle, gastric body, gastric antrum, duodenum and total time. The volume of water needed to flush the esophagus, gastric fundus, gastric angle, gastric body, gastric antrum, duodenum and in total were both significantly less in Group A compared to Group B (P < 0.01).
Table 3
Flush times and volume of flush water
| Group A(n = 354) | Group B(n = 169) | P-value |
Flush times | | | |
Esophagus | 0.05 ± 0.43 | 0.09 ± 0.33 | 0.271 |
Gastric fundus | 0.16 ± 0.44 | 0.74 ± 0.93 | < 0.01 |
Gastric angle | 0.04 ± 0.24 | 0.17 ± 0.38 | < 0.01 |
Gastric body | 0.38 ± 0.77 | 1.12 ± 1.40 | < 0.01 |
Gastric antrum | 0.10 ± 0.37 | 0.60 ± 0.79 | < 0.01 |
Duodenum | 0.05 ± 0.22 | 0.28 ± 0.51 | < 0.01 |
Total times | 0.78 ± 1.36 | 3.01 ± 2.62 | < 0.01 |
Volume of flush water(ml) | | | |
Esophagus | 0.79 ± 4.87 | 2.75 ± 10.07 | < 0.01 |
Gastric fundus | 5.11 ± 14.62 | 28.31 ± 39.15 | < 0.01 |
Gastric angle | 0.90 ± 7.04 | 3.96 ± 12.36 | < 0.01 |
Gastric body | 15.99 ± 35.33 | 42.91 ± 68.75 | < 0.01 |
Gastric antrum | 3.68 ± 15.11 | 19.76 ± 35.32 | < 0.01 |
Duodenum | 1.38 ± 6.35 | 5.80 ± 15.41 | < 0.01 |
Total volume | 27.86 ± 53.57 | 103.50 ± 128.03 | < 0.01 |
Time Required For Endoscopy Examination
Figure 4 shows the mean overall time for all gastroscopies in Group A (5.73 ± 2.65 min) was shorter than in Group B (6.76 ± 3.13 min). The difference between the two groups (P < 0.01) was significant.
The complications of premedication with mixed solution of reformulated simethicone emulsion and 5% NaHCO3 solution
The incidence percentage for abdominal pain (0.8% vs 4.1%, P < 0.05) and distension (5.4% vs 19.5%, P < 0.01) during EGD were significantly higher in Group B than they in Group A (Fig. 5a). There was no significant difference between Group A and Group B for the percentage of patients who had no adverse response (57.6% vs 55.0%) and nausea (34.5% vs 29.6%) during EGD.
The incidence of abdominal pain (10.1% vs 1.7%), distension (9.5% vs 6.5%) and nausea (2.4% vs 1.7%) after EGD occurred significantly more often in Group B than in Group A (P < 0.01) as shown in Fig. 5b. In addition, the percentage of patients who had no adverse response (82.8% vs 77.5%) is significantly higher in Group A (P < 0.01).